From e247dbce5cc747a714e8dcbd6b3f442cc2a284cf Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 9 Aug 2010 17:19:28 -0700 Subject: [PATCH] vmscan: simplify shrink_inactive_list() Now, max_scan of shrink_inactive_list() is always passed less than SWAP_CLUSTER_MAX. then, we can remove scanning pages loop in it. This patch also help stack diet. detail - remove "while (nr_scanned < max_scan)" loop - remove nr_freed (now, we use nr_reclaimed directly) - remove nr_scan (now, we use nr_scanned directly) - rename max_scan to nr_to_scan - pass nr_to_scan into isolate_pages() directly instead using SWAP_CLUSTER_MAX [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Reviewed-by: Johannes Weiner Reviewed-by: Rik van Riel Cc: Dave Chinner Cc: Chris Mason Cc: Nick Piggin Cc: Rik van Riel Cc: Johannes Weiner Cc: Christoph Hellwig Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Andrea Arcangeli Cc: Michael Rubin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 232 +++++++++++++++++++++++++--------------------------- 1 file changed, 112 insertions(+), 120 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 594eba8a44c0..8522327bd04f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1136,15 +1136,21 @@ static int too_many_isolated(struct zone *zone, int file, * shrink_inactive_list() is a helper for shrink_zone(). It returns the number * of reclaimed pages */ -static unsigned long shrink_inactive_list(unsigned long max_scan, +static unsigned long shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, struct scan_control *sc, int priority, int file) { LIST_HEAD(page_list); struct pagevec pvec; - unsigned long nr_scanned = 0; + unsigned long nr_scanned; unsigned long nr_reclaimed = 0; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); + struct page *page; + unsigned long nr_taken; + unsigned long nr_active; + unsigned int count[NR_LRU_LISTS] = { 0, }; + unsigned long nr_anon; + unsigned long nr_file; while (unlikely(too_many_isolated(zone, file, sc))) { congestion_wait(BLK_RW_ASYNC, HZ/10); @@ -1159,129 +1165,115 @@ static unsigned long shrink_inactive_list(unsigned long max_scan, lru_add_drain(); spin_lock_irq(&zone->lru_lock); - do { - struct page *page; - unsigned long nr_taken; - unsigned long nr_scan; - unsigned long nr_freed; - unsigned long nr_active; - unsigned int count[NR_LRU_LISTS] = { 0, }; - int mode = sc->lumpy_reclaim_mode ? ISOLATE_BOTH : ISOLATE_INACTIVE; - unsigned long nr_anon; - unsigned long nr_file; - if (scanning_global_lru(sc)) { - nr_taken = isolate_pages_global(SWAP_CLUSTER_MAX, - &page_list, &nr_scan, - sc->order, mode, - zone, 0, file); - zone->pages_scanned += nr_scan; - if (current_is_kswapd()) - __count_zone_vm_events(PGSCAN_KSWAPD, zone, - nr_scan); - else - __count_zone_vm_events(PGSCAN_DIRECT, zone, - nr_scan); - } else { - nr_taken = mem_cgroup_isolate_pages(SWAP_CLUSTER_MAX, - &page_list, &nr_scan, - sc->order, mode, - zone, sc->mem_cgroup, - 0, file); - /* - * mem_cgroup_isolate_pages() keeps track of - * scanned pages on its own. - */ - } - - if (nr_taken == 0) - goto done; - - nr_active = clear_active_flags(&page_list, count); - __count_vm_events(PGDEACTIVATE, nr_active); - - __mod_zone_page_state(zone, NR_ACTIVE_FILE, - -count[LRU_ACTIVE_FILE]); - __mod_zone_page_state(zone, NR_INACTIVE_FILE, - -count[LRU_INACTIVE_FILE]); - __mod_zone_page_state(zone, NR_ACTIVE_ANON, - -count[LRU_ACTIVE_ANON]); - __mod_zone_page_state(zone, NR_INACTIVE_ANON, - -count[LRU_INACTIVE_ANON]); - - nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; - nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; - __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon); - __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file); - - reclaim_stat->recent_scanned[0] += nr_anon; - reclaim_stat->recent_scanned[1] += nr_file; - - spin_unlock_irq(&zone->lru_lock); - - nr_scanned += nr_scan; - nr_freed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC); - - /* - * If we are direct reclaiming for contiguous pages and we do - * not reclaim everything in the list, try again and wait - * for IO to complete. This will stall high-order allocations - * but that should be acceptable to the caller - */ - if (nr_freed < nr_taken && !current_is_kswapd() && - sc->lumpy_reclaim_mode) { - congestion_wait(BLK_RW_ASYNC, HZ/10); - - /* - * The attempt at page out may have made some - * of the pages active, mark them inactive again. - */ - nr_active = clear_active_flags(&page_list, count); - count_vm_events(PGDEACTIVATE, nr_active); - - nr_freed += shrink_page_list(&page_list, sc, - PAGEOUT_IO_SYNC); - } - - nr_reclaimed += nr_freed; - - local_irq_disable(); + if (scanning_global_lru(sc)) { + nr_taken = isolate_pages_global(nr_to_scan, + &page_list, &nr_scanned, sc->order, + sc->lumpy_reclaim_mode ? + ISOLATE_BOTH : ISOLATE_INACTIVE, + zone, 0, file); + zone->pages_scanned += nr_scanned; if (current_is_kswapd()) - __count_vm_events(KSWAPD_STEAL, nr_freed); - __count_zone_vm_events(PGSTEAL, zone, nr_freed); - - spin_lock(&zone->lru_lock); + __count_zone_vm_events(PGSCAN_KSWAPD, zone, + nr_scanned); + else + __count_zone_vm_events(PGSCAN_DIRECT, zone, + nr_scanned); + } else { + nr_taken = mem_cgroup_isolate_pages(nr_to_scan, + &page_list, &nr_scanned, sc->order, + sc->lumpy_reclaim_mode ? + ISOLATE_BOTH : ISOLATE_INACTIVE, + zone, sc->mem_cgroup, + 0, file); /* - * Put back any unfreeable pages. + * mem_cgroup_isolate_pages() keeps track of + * scanned pages on its own. */ - while (!list_empty(&page_list)) { - int lru; - page = lru_to_page(&page_list); - VM_BUG_ON(PageLRU(page)); - list_del(&page->lru); - if (unlikely(!page_evictable(page, NULL))) { - spin_unlock_irq(&zone->lru_lock); - putback_lru_page(page); - spin_lock_irq(&zone->lru_lock); - continue; - } - SetPageLRU(page); - lru = page_lru(page); - add_page_to_lru_list(zone, page, lru); - if (is_active_lru(lru)) { - int file = is_file_lru(lru); - reclaim_stat->recent_rotated[file]++; - } - if (!pagevec_add(&pvec, page)) { - spin_unlock_irq(&zone->lru_lock); - __pagevec_release(&pvec); - spin_lock_irq(&zone->lru_lock); - } - } - __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); - __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); + } - } while (nr_scanned < max_scan); + if (nr_taken == 0) + goto done; + + nr_active = clear_active_flags(&page_list, count); + __count_vm_events(PGDEACTIVATE, nr_active); + + __mod_zone_page_state(zone, NR_ACTIVE_FILE, + -count[LRU_ACTIVE_FILE]); + __mod_zone_page_state(zone, NR_INACTIVE_FILE, + -count[LRU_INACTIVE_FILE]); + __mod_zone_page_state(zone, NR_ACTIVE_ANON, + -count[LRU_ACTIVE_ANON]); + __mod_zone_page_state(zone, NR_INACTIVE_ANON, + -count[LRU_INACTIVE_ANON]); + + nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; + nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; + __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file); + + reclaim_stat->recent_scanned[0] += nr_anon; + reclaim_stat->recent_scanned[1] += nr_file; + + spin_unlock_irq(&zone->lru_lock); + + nr_reclaimed = shrink_page_list(&page_list, sc, PAGEOUT_IO_ASYNC); + + /* + * If we are direct reclaiming for contiguous pages and we do + * not reclaim everything in the list, try again and wait + * for IO to complete. This will stall high-order allocations + * but that should be acceptable to the caller + */ + if (nr_reclaimed < nr_taken && !current_is_kswapd() && + sc->lumpy_reclaim_mode) { + congestion_wait(BLK_RW_ASYNC, HZ/10); + + /* + * The attempt at page out may have made some + * of the pages active, mark them inactive again. + */ + nr_active = clear_active_flags(&page_list, count); + count_vm_events(PGDEACTIVATE, nr_active); + + nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC); + } + + local_irq_disable(); + if (current_is_kswapd()) + __count_vm_events(KSWAPD_STEAL, nr_reclaimed); + __count_zone_vm_events(PGSTEAL, zone, nr_reclaimed); + + spin_lock(&zone->lru_lock); + /* + * Put back any unfreeable pages. + */ + while (!list_empty(&page_list)) { + int lru; + page = lru_to_page(&page_list); + VM_BUG_ON(PageLRU(page)); + list_del(&page->lru); + if (unlikely(!page_evictable(page, NULL))) { + spin_unlock_irq(&zone->lru_lock); + putback_lru_page(page); + spin_lock_irq(&zone->lru_lock); + continue; + } + SetPageLRU(page); + lru = page_lru(page); + add_page_to_lru_list(zone, page, lru); + if (is_active_lru(lru)) { + int file = is_file_lru(lru); + reclaim_stat->recent_rotated[file]++; + } + if (!pagevec_add(&pvec, page)) { + spin_unlock_irq(&zone->lru_lock); + __pagevec_release(&pvec); + spin_lock_irq(&zone->lru_lock); + } + } + __mod_zone_page_state(zone, NR_ISOLATED_ANON, -nr_anon); + __mod_zone_page_state(zone, NR_ISOLATED_FILE, -nr_file); done: spin_unlock_irq(&zone->lru_lock);